Buffing hood



Nov. 30, 1937. G EDA T 2,100,344

BUFFING' HOOD Filed Jan. 22, 1937 jnventor; Gustav jfMedart, .by

'Patented Nov. 30, 1937 UNITED STA anean 12 Claims.

My invention relates to buffing hoods; and particularly to such as are used in dental laboratories and likeplaces, where delicate, fragile, and expensive articles are to be polished. Among its 5 salient objects are; first, to provide means for safely catching fragile objects which are thrown by buffing wheels while being polished; second, *to furnish a buffing hood in which all the walls are of resilient and readily stretchable material, and wherein there are no unyield'ng surfaces likely to be struck by flying objects; third, to supply convenient means for maintaining the material of the walls of the hood in a desired degree of tension; fourth, to limit the stretching of the walls of the device chiefly to their marginal edges, where there is the least likelihood of their being struck by flying objects; fifth, to devise improved means for loosening and recovering any solidified polishing material which may be deposited; and, sixth, to accomplish the aforesaid, and related objects, by means of very simple, durable, and dependable Construction.

My objects have been attained in the manner illustrated in the acc'ompanying drawing, in which Figure 1 is a side elevation of my improved bufing hood;

Figure 2 is a front elevation of said invention; Figure 3 is a central, longitudinal section oi i the device, taken on the plane 3-3 of Fig. 2;

Figure 4 is a cross section of the Construction taken on stepped planes positioned as indicated by the broken line 4-4 of Fig. 1;

Figure 5 is a side elevation of one of the two side frames of the device, by which the resilient material is supported and maintained in position;

Figure 6 is a front elevation of one form of cross-bar, by means of which the frames of the 40 device may be spaced; and

Figure 7 is a front elevation of an alternate form of cross-bar.

Similar reference numerals refer to similar parts throughout the several Views.

It is well known that the polishing of dentures in dental laboratories, as an example of the work for which my device is Well suited, is a risky operation. such objects are delicate, fragile, and often very costly. The high speed buffing wheel is quite likely at times, to pull the work out of the hands of the operator, and to throw it violently against suriaces where, hitherto, it is almost certain to be ruined or greatly damaged. My buffing hood overcomes this danger, by safely catching objects thrown by the wheel, and its use practically assures freedom from damage due to this cause.

Passing to a detailed description of my invention, andreferring to the accompanying drawing, I construct the hood entirely of Very resilient' soft rubber, supported on a pair of opposed spaced frames of the desired conguration, such as shown in Fig. 5. I prefer to construct these frames mostly of tubular material, as indicated at l I. This material is bent to the desired form," and joined at the extremities by a relatively small metallic plate !2. This plate also serves to position one of the necessary cross-bars of the device. Projecting lugs or ears !3, are welded to the outer peripheries of the tubular frames at` appropriate points, for positioning the other cross-bars required. In the form of my invention that has been selected by illustration, metallc feet M are needed; and these may Conveniently take a sphercal shape at the ends of rods I 5, the latter also being welded to the outer periph eries of the frames at appropriate points. Plate |2 and lugs l3 are suitably perforated, as at !6, for engaging the ends of the cross-bars with which they are to be used.

The frames are completely surrounded by, and imbedded in, soft stretchable rubber, and preferably are vulcanized thereto. This Construction is clearly indicated in cross section in Fig. 4; the rubber portions which enclose the tubular frames, being integral with side walls H, and with the curved top, bottom, and back cross-Walls !8, I 9

and 2! respectively. All of these walls are made thinner adjacent their peripheries as indicated at 22; so that, when they are subjected to tension,

the stretching will take place chiefiy at these thinned points adjacent the margins of the walls.

For spacing the two metallic frames, subjecting the cross-walls to tension, and completing the assembly of the device, I employ three cross-bars' of adjustable length. These may be of any suitable form, and three types are illustrated. These bars should be provided with a fiange 23 at each end, adapted for seating upon plates I2 and lugs 13; and their extrem'ties should be suitable for engaging the perforations in these plates and lugs.

One such form of cross-bar is shown in Fig. 2, and this type is particularly suitable for use at both the front and rear of the device. This cross-bar takes the form of right and left-hand threaded screws, With a capstan head 24 at the center. These respective screw parts engage right and left-hand threaded flanged sleeves 25 and 26 respectively. These sleeves are provided with co-axial squared heads 21, adapted to engage the square perforations !6, in plates !2 and lugs !3.

Another form of cross-bar is shown by itself in Fig. 6. This comprises a flanged bar 28 having, at one extremity, a co-axial screw 29 engaging an internally threaded flanged sleeve SI. One extremity of this composite cross-bar is provided with squared head 32, and the other extremity is provided with a cylindrical screw-s1otted head 33.

A third form of cross-bar is shown in Fig. '7. This has a flange 23 adjacent each extrenity, and co-axial cylindrical ends 34. may be used with any desired number or thickness of washers 35, which afford Variation oftheeffective length of the bar. It is used by merely stretching the rubber walls of the device sumciently to enable ends ,34 to be inserted in ;t he perforations of plates !2 and lugs [3. It is immaterial whether these perforationsare squareor round, since the barfends will engage the perforations properly in either case. i

A variably positionablemetallic guard 35 may be used with across-bar of the type shown in Fi 6, and is held by frictional grip in any desired position.

Fgs. land 3 indicate how the device may be whel-indicated by dotted lines 31. The buffing 30 l lower periphery of the wheel; andif the work isaccomplished byholding the work against the should bepulledout of the operator's hands, it wil1,be thrown backwardly against thejnterior curved back wall 2 l ,i or bottom wall !9 of the de- Vice. All ofthese wall surfacesare of resilient rubber in tension, and are spaoed from any solid ,unyielding part. The wallsthereforewill yield,

- and Stretch in proportion tothe impact of the thrown object; and the latter will be caught as though by aresilient bag, without damage. degree of resiliency of the `cross walls, may be The regulated by adjusting the length of the three crossbars Theforward lower part of the device provides a tray at 38; into which semi-fluid polishing material will drainand collect, sothat it may be used repeatedly. This, of course, effects a substantial interier walls of the device, or withintray z f, may

,be easily removed, without scraping or chipping,

by merelybrealgingit up by flexing the rubber clear to those familiar with'the art involved, I

walls against which it is deposited.

Having thus fully disclosed my invention in a manner that willrnakeits Construction and use claim z 1. A buffing hood comprising; adjustably spacedside walls connected by cross walls under tension all of said walls b'eingof resilient and This form of bar able material; and cross bars of adjustable length variably spacing the side walls; said bars being 'outside of, and materially spaced from, the cross walls. i

r 4; A bufling hood comprsing; a pair of opposed outlineisideframes; resilient and easily Stretchable material completely enclosng the frames -and--supported thereby, constituting side walls connected by cross walls integral therewith; and

means for Variably spacing the frames-to -put the material .ofthe cross walls under tension.

5. Construction as defined by claim 4,. wherein the material of the wall portions which are sub ject to internal impacts is relatively thin arijacent the wall margins.

6. Construction as defined by claimf4wherein the material of the wall portions which are subject to internal impacts, is free to .deflect outwardly for considerable ,distances 7. Construction as defined by claim 4w herein the spacng means include cross bars of adjustable eective length.

84 Construction as defined by claim 4, wherein,

the spacing means include cross bars having screw threads for adjusting theireffective length.

9. Construction as defined byclaim 4, wherein the spacing means include cross barsupon which washers may be Variouslypositioned for adjust:

ing the effectivelength of the bars.

10. Construction as defined by claim 4 wherein a bottom portion of the device constitutes a tray which extends forwardly from any normal position of the bufling wheel with whichthe device is i d pted b u e 11; Construction as defined by claim 4, wherein abottom portion of the device constitutes a tray which extends orwardlyfrom any normal position of the bufiing wheel with which the device is adapted to be used; and wherein the bottomcross wall, below and to the rear of said wheel position, is spaced from outside surfaces, and above said tray portion.

12. Construction as defined by claim 4, wherein said resilient material is of the nature of rubber; and wherein the frames are embedded' in, and vulcanizedto, said material.

GUSTAV H. MEDART. 

